US2699728A - Oil burner - Google Patents

Description

OIL BURNER 3 Sheets-Sheet 2 Filed Oct. 4, i

IRES

3 2 w 6 D 5 \Lm zz 9 D T MW Wm. 1 MB O 5 W BIIY 7 D 8 1 8 m 0 W7, m 7 w 5 4 oo 0 5 1 5 7 A/ a 9 5 W 7 1 8 m 0 7 8 4 TOR N EYS Jan. 18, 1955 GETZ ETAL 2,699,728

OIL BURNER Filed 001;. 4, 1950 3 Sheets-Sheet 3 DELMOND L. GETZ 8} ROBERT 0- HEDGES ATTORNEYS United States Patent OIL BURNER Delmond L. Getz and Robert 0. Hedges, Springfield,

Ohio, assignors to The Steel Products Engineering Cornpany, Springfield, Ohio, acorporation of Ohio Application October 4, 1950, Serial No. 188,450 4 Claims. (Cl. 10 3-38) This invention relates to oil burners for heating purposes and the like.

The invention has particular relation to an oil burner in which the liquid fuel is supplied at a metered rate to an atomizing pump where it is mixed with air for delivery to a flow Stabilizing device in which the fuel is separated from the air and then delivered to the nozzle in a steady and constant flow under [balanced pressure conditions unaifected by pulsations in the supply pressure for remixing with the air and combustion.

One of the principal objects of the invention is to provide an oil metering pump adapted to be incorporated in such an oil burner which includes a simple adjusting mechanism for varying the fuel output of the pump without otherwise changing its operating characteristics or requirements.

Another object is to provide a metering pump of simple construction for an oil burner which -is operable at slow speeds to deliver a metered supply of liquid fuel and which includes coaxial pistons and 'a rocker member cooperating With a crank to produce combined reciprocating and oscillating movements of the pistons for properly timed cooperative registry with suction and discharge ports in the housing of the pump.

'It is also an object of the invention to provide such a pump wherein the oscillating movement of the pistons effects desired control of the suction and dischargeports of their respective cylinders and wherein "the operating crank or drive shaft includes an adjustable eccentric mechanism for varying the stroke of the pistons to determine the output of the pump.

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings- Fig. l is a view partly in side elevation and partly broken away showing an oil burner in accordance with the invention;

Fig. 2 is a rear view of the oil burner with a portion of the casing broken away;

Fig. 3 is an enlarged view partly in side elevation and partly broken away in section on the line 3-3 of Fig. 4 showing the oil pump of the oil burner of Figs. 1 and 2;

Fig. 4 is a sectional view through the lower part of the pump taken on the line 4-4 of Fig. 8 and looking upwardly;

Fig. 5 is a detail view taken in section approximately on the line 55 of Fig. 3 to show the crank shaft and associated operating parts of the pump;

Fig. 6 is a detail view of the lower end of the crank shaft;

Fig. 7 is an enlarged fragmentary section on the line 7--7 of Fig. 6;

Fig. 8 is a section on the line 8-8 of Fig. 3;

Fig. 9 is an elevational view of the reverse side of the pump from that shown in Fig. 3, with portions broken away to show details of internal construction;

Fig. 10 is a fragmentary view in section on the line 10-10 of Fig. 4 illustrating the construction and operation of the oil passages and one of the pistons of the metering pump, the view showing the angular position of the piston on the suction stroke;

Figs. 11 and 12 are views similar to Fig. 10 showing the angular positions of the piston at the end of each stroke and during the pressure stroke respectively; and

2,699,728 Patented Jan. 18, 1955 Fig. 13 is an enlarged fragmentary view of the operating end of the oil shutoff valve.

Referring to the drawings, which illustrate a preferred embodiment of the invention, Figs. 1 and 2 show the general construction of an oil burner mcorporating an oil metering pump in accordance with the invention, reference being madein this connection 'to our application Serial No. 2,713 filed January 16, 1948, of which the present application is a continuation in part which is now issued as Patent No. 2,632,499 on March 24, 1953. The oil burner includes a main casing 13 having a base 14 and supporting an oil metering pump 15, an atomizing air pump 16 and a fan or blower 17, all-driven by an electric motor 20 through a shaft 21, and an adjustable damper22 is provided for regulating the supply of :air to the blower 17. The oil from the supply tank (not shown) is initially admitted to the metering pump by way of an inlet connection 24, and the pump 15 supplies this oil at an adjustable metered rate to the atomizing pump 16, where it is mixed with air and then passed to a flow stabilizing device 25 by means of a pipe or tube 26.

In the flow stablizing device 25, as is described in detail in the 'above Patent No. 2,632,499, the atomized mixture is separated into air and liquid fuel for separate transmission to the nozzle 30 in the combustion head 31 at the outer end of the blast tube 32. The air flows to the nozzlethrough a tube 33 to serve as primary air for mixture with the oil, which flows to the nozzle through a smaller tube 34 within the tube 33. At the nozzle, the liquid oil and primary air are mixed and ignited by a spark induced between the electrodes 35, which are provided with the proper high tension current by the transformer 36 on casing 13, and secondary air is supplied to the combustion head from the blower 1 7, the combustion head 31 having fins 37 thereon for causing the secondary air to swirl as it is discharged from the blast tube.

The construction and operation of the oil metering pump 15 are shown in detail in Figs. 3 to 13. The casing 40 of the pump includes a chamber 41 which is closed at its outer end by a cap 42 carrying the inlet'connection 24, and this cap also supports :a strainer 43 for filtering the incoming oil as shown in Fig. 8. From the chamber 41, the oil fiows by way of a passage 44 into the main chamber 45 of the pump which contains the drive mechanism for the pump. An adjustable air vent for the chamber 45 is shown at 46 in Fig. 3, and the chamber is also provided with an access port having a-closure 47.

Communication between the chamber 41 and passage 44 is controlled by a shutoff valve 50 in the form of a rod slidable in the casing 40 and having a tapered end 51 (Fig. 13) adapted to seat within the correspondingly tapered upper end of the passage 44. As shown in Fig. 13, this tapered end of the valve 50 is formed with a circumferential groove 52 which receives a rubber O-ring 53 for assuring an adequately tight seal. Also, the valve 50 is provided at a position intermediate its ends with a further circumferential groove 54on which is mounted an 'O-ring 55 to seal against escape of oil upwardly from the chamber 41. p

The valve 50 is operated by pressure from the atomizing air pump 16, and the upper-end of the pump housing is formed to define a pressure chamber 604301 apiston 61 secured to the valve rod 50. A spring 62 is positioned between the upper side of the piston 61 and the cap 63 for chamber 60, which has a gasket 64, and the spring 62 normally urges the piston and valve downwardly to effect seating of the tapered end 51 of the rod in passage 44 as shown in Fig. 13. A passage 65 (Fig.9) is formed in casing 40 for connection with the discharge side of the atomizing pump 16 to supply pressure to the under side 'of piston 61 for moving the piston'a'nd valve 50 upwardly against springl62 to open the valve for flow of oil from the chamber 41 into the chamber 45, and the O-ring 55 also seals against escape of this pressure along the valve rod 50 to chamber 45. An additional passage 66 is formed in the casing 40 for connecting the low pressure side of piston 61 to the intake of the atomizing pump, and it opens into chamber '60 at 67 below the gasket 64. The passages 65 and 66 have ports 68 and 69 respectively in the side of casing 40 for registry with corresponding ports in the housing of air pump 16, as described in detail in the above application Serial No. 2,713 and also in our copending application Serial No. 188,451, filed of even date herewith and assigned to'the same assignee as this application.

The pump casing 40 is formed in its lower part to define a pair of coaxial cylinders each having a piston 77 mounted for reciprocating and oscillating movement therein. Each cylinder is provided with an intake port 80 from chamber 45 and an outlet port 81 spaced angularly from port 80 and leading to a passage 82 in the casing having a discharge port 83 connecting with a groove 84 in the outer surface of the housing which is adapted to register with a corresponding intake port in the air pump 16. A plug 85 serves as a removable closure for the outer end of each cylinder 75, and each pistou 77 has a pair of grooves 86 and 87 in its outer surface adapted to register with ports 80 and 81, respectrvely, these grooves being spaced angularly by an amount different from the angular spacing of ports 80 and 81 so that only one groove and port can be in registry at the same time.

The reciprocating movement of the pistons 77 in cylinders 75 is effected by means of a crank shaft assembly within the chamber 45. This crank shaft assembly includes a shaft 90 having its upper end journaled in the casing 40 and with its lower end supported in a bearing 91 carried by the bottom cover 92 of the casing, which is shown as having therein a drain port and plug 93, and a screw plug 94 covers the upper end of the shaft. A sleeve 95 is pinned to the shaft 90 and is formed with a worm gear 96 meshing with a worm portion 97 of the drive shaft 21. The shaft 90 includes an eccentric portion 99 on which is mounted an eccentric sleeve 100 which is adapted to engage the inner ends of the pistons 77 as this sleeve rotates on the crank shaft to effect the deslred reciprocating movement of the pistons.

An adjustable connection is provided between the eccentric sleeve 100 and the eccentric portion 99 of the crank shaft in order to vary the throw of the eccentric and hence the length of the working stroke of the pistons. This adjustable connection includes a flanged bushing 101 pinned at 102 to the eccentric shaft portion 99. The bushing 101 carries a plunger pin 105 loaded by means of a spring 106 as shown in Fig. 7 and adapted for releasable engagement in a selected one of a series of holes 107 in the adjacent end portion of the eccentric sleeve 100. Thus by withdrawing the pin 105 against spring 106 and rotating the sleeve 100 and bushing 101 with respect to each other, the effective throw of the eccentric sleeve can be adjusted as desired.

A rocker 110 cooperates with the crank shaft assembly to provide for oscillating movement of the pistons 77 at each end of their reciprocating strokes in such manner as to cause the grooves 86 to register with ports 80 during the suction strokes of the pistons and to cause grooves 87 to register with the ports 81 during the pressure strokes of the pistons. The rocker 110 is carried by a portion 111 of reduced diameter at the inner end of each piston, and it is secured thereto by means such as a snap ring 112 as shown in Figs. 3 and 4. In addition, the portion 111 of each piston has a flattened side 113 as shown in Fig. 8, and the receiving hole therefor at either side of the rocker is correspondingly shaped to key the rocker and pistons together for the desired oscillating movement.

This oscillating movement of the rocker 110 and pistons 77 is effected in timed relation with the reciprocating movement of the pistons by means of upwardly projecting cam lobes 115 arranged at diagonally opposite positions on the sides of the rocker for cooperation with a radially projecting cam arm 116 on the gear sleeve 95. As shown in Figs. 5 and 8, the cam arm 116 alternately engages and depresses the lobes 115 as the crank shaft rotates to cause the pistons to oscillate as a result of their keyed connection at 113 with the rocker. The positions of the cam lobes and the angular position of the cam arm 116 with respect to the eccentric sleeve 100 are so correlated that the cam arm 116 alternately engages the lobes 115 at the end of each stroke of the pistons so that the rocker and pistons are caused to oscillate while the eccentric sleeve is passing over dead center, and the rocker and pistons accordingly do not oscillate during the reciprocating strokes of the pistons.

The operation of pistons 77 and the cooperating ac tion of grooves 86 and 87 therein with the ports 80 and 81 in the cylinders 75 are best seen in Figs. 10 to 12. Fig. 10 shows the relative angular positions of the cylinder and piston during the suction stroke, with the groove 86 in registry with inlet port 80 to draw oil from chamber 45 into the space at the outer end of the cylinder, and with the groove 87 out of registry with the outlet port 81. Fig. 11 shows the angular positions of the cylinder and piston at the end of each stroke during passage of the eccentric sleeve 100 over dead center, and it will be noted that both of grooves 86 and 87 are out of registry with ports 80 and 81. Fig. 12 shows the angular positions of the piston and cylinder during the discharge stroke of the piston, with the groove 87 in registry with the outlet port 81 for discharging the oil from the cylinder into the passage 82, and with the groove 86 out of registry with inlet port 80. It will be understood that when either piston is in the position shown in Fig. 10, the other piston will be in the position shown in Fig. 12, thus providing for alternate suction and pressure strokes to deliver a substantially constant supply of oil to the atomizing pump 16 at a metered rate corresponding to the size and stroke of the cylinders and the speed of the motor 20.

As shown in Figs. 1 and 2, the metering pump 15 is mounted on one end of the oil burner assembly and next to the air atomizing pump 16 to provide the desired registry between the separate ports in the housings of the two pumps as described. Proper alignment of the two pump housing is readily obtained by the provision of suitable dowels 120 registering in holes 121 in the pump housing 40 and in corresponding receiving holes in the housing of the atomizing pump 16, and tapped holes 122 are provided in the housing 40 for receiving the mounting bolts, one of which is shown at 123 in Fig. 8. The hole 125 in the housing 40 receives the pivot shaft for a valve in the atomizing pump 16 as shown in detail in the above noted copending applications.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the in.- vention which is defined in the appended claims.

What is claimed is:

1. A metering pump adapted for use in an oil burner comprising a casing defining a main chamber and a pair of spaced coaxial cylinders, each said cylinder having a suction inlet from said chamber and a discharge outlet angularly spaced from said inlet about the axis of said cylinder, a piston in each said cylinder, each'said piston having a pair of grooves extending axially in the outer surface thereof and spaced angularly from each other about the axis of said piston by an amount different from the angular spacing of said inlet and said outlet to prevent simultaneous registry of said grooves with said inlet and outlet, crank means for causing reciprocating movement of said pistons in said cylinders, cooperating means carried by said pistons and said crank means for causing oscillating movement of said pistons about the axes thereof through an angle substantially equal to said angular spacing of said grooves therein, said cooperating means being arranged for operation in timed relation with said reciprocating movement of said pistons to effect said oscillating movement only at each end of each stroke of said pistons to effect registry of said grooves therein with said inlets on the suction stroke and said outlets on the pressure stroke, and means for supplying oil to said chamber.

2. A metering pump adapted for use in an oil burner comprising a casing defining a main chamber and a pair of spaced coaxial cylinders, each said cylinder having a suction inlet from said chamber and a discharge outlet angularly spaced from said inlet about the axis of said cylinder, a piston in each said cylinder, each said piston having grooves in the outer surface thereof spaced angularly from each other about the axis of said piston by an amount different from the angular spacing of said inlet and said outlet, a rocker connected to said pistons for causing oscillating movement of said pistons about the axes thereof, a crank mounted for rotation in said chamber to cause reciprocating movement of said pistons, and cooperating cams on said rocker and crank for effecting said oscillating movement of said pistons at each end of each stroke thereof through an angle substantially equal to said angular spacing of said grooves therein to cause said grooves therein to register with said inlets on the suction stroke and said outlets on said pressure stroke.

3. A metering pump adapted for use in an oil burner comprising a casing defining a main chamber and a pair of spaced coaxial cylinders, each said cylinder having a suction inlet from said chamber and a discharge outlet angularly spaced from said inlet about the axis of said cylinder, a piston in each said cylinder, each said piston having a pair of grooves in the outer surface thereof spaced angularly'froni each other about the axis of said piston by an amount different from the angular spacing of said inlet and said outlet to prevent simultaneous registry of said grooves with said inlet and outlet, a crank shaft including an eccentric portion extending between said pistons for causing reciprocating movement of said pistons in said cylinders, means for causing oscillating movement of said pistons about the axes thereof at each end of each stroke thereof through an angle substantially equal to said angular spacing of said grooves therein to effect registry of said grooves therein with said inlets on the suction stroke and said outlet on the pressure stroke, means for supplying oil to said chamber, and means forming an adjustable connection between said eccentric portion of said crank shaft and the remainder of said crank shaft providing for changing the eifective throw of said eccentric portion and thereby for changing the length of the reciprocating strokes of said pistons to regulate the output of said pump.

4. A metering pump adapted for use in an oil burner and comprising a casing defining a main chamber and a pair of spaced coaxial cylinders, each said cylinder having a suction inlet from said chamber and a discharge outlet angularly spaced from said inlet about the axis of said cylinder, a piston in each said cylinder, each said piston having grooves in the outer surface thereof spaced angularly from each other about the axis of said piston by an amount dilferent from the angular spacing of said inlet and said outlet, a rocker connected to said pistons for causing oscillating movement of said pistons about the axes thereof, a shaft rotatable in said chamber, said shaft including a portion eccentric with respect to the rotational axis thereof, an eccentric sleeve rotatable on said eccentric shaft portion and adapted to engage the ends of said pistons for causing reciprocating movement thereof, means for releasably securing said sleeve to said shaft in a selected relative angular position thereof in accordance with the desired efiective throw of said sleeve and the resulting stroke of said pistons, and cooperating cams on said rocker and said shaft for elfecting said oscillating movement of said pistons at each end of each stroke thereof through an angle substantially equal to said angular spacing of said grooves therein to cause registry of said grooves therein with said inlets on the suction stroke and said outlets on the pressure stroke.

References Cited in the file of this patent UNITED STATES PATENTS 138,622 Eikemeyer May 6, 1873 973,353 Inokuty Oct. 18, 1910 1,477,300 Thrift Dec. 11, 1923 1,817,051 Williams Aug. 4, 1931 1,843,733 Powell Feb. 2, 1932 FOREIGN PATENTS 168,816 Great Britain 1921

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